97 Fun Facts About Roofing

What are the sloping beams that run from a roof's ridge down to the top of its walls called?

Rafters push outward on the walls as well as down, so builders link the feet of each opposing pair with a tie beam to stop the walls spreading.

US fire insurers campaigned against which roofing, helping asphalt take over?

Wood shingles were a known fire hazard, so insurers pressed to get rid of them; asphalt shingles, which the Grand Rapids roofer Henry Reynolds began cutting in 1903, were cheap, fire-resistant and ready to step in.

Early asphalt roofing was made more durable by pressing what into its surface?

Slate granules, crushed and pressed into the asphalt, toughen the surface and block the sunlight that breaks asphalt down; the underside is dusted with sand, talc or mica so bundled shingles don't stick.

By 1882, which country was quarrying 92% of the United Kingdom's slate?

Wales produced 92% of UK slate in 1882; its quarrymen worked in small gangs that struck a monthly bargain for a patch of rock, so they saw themselves as contractors and unions were slow to form.

Which slate quarry near Bethesda, once the largest in the world, shares its name with its owners' mock-Norman castle?

Penrhyn Quarry was built up by Richard Pennant with his family's Jamaican sugar fortune; by the end of the 1800s it was the largest slate quarry in the world, worked by nearly 3,000 men.

Slate splits into smooth flat sheets for roofing because of a property called what?

Fissility is a rock's tendency to split along flat parallel planes; a slate splitter taps a chisel into a block about three inches thick and splits it again and again into thin roofing sheets.

The Globe Theatre burned down in 1613 when a stage cannon lit its roof of what?

Thatch caught a spark from a cannon fired during Henry VIII, and the playhouse burned to the ground; by one surviving account the only casualty was a man whose flaming breeches were doused with ale.

What is the low wall that rises above the roofline around a flat roof called?

A parapet began as a soldier's breast-high defensive wall, its name from the Italian for 'guard the chest'; on a roof it now serves as a guard rail, hides equipment and helps keep fire from spreading.

Which French ruler's rebuilding of Paris made the mansard roof fashionable in the 19th century?

Napoleon III's Second Empire rebuilding of Paris under Haussmann put mansard roofs on boulevards across the city, and the look was copied worldwide as Second Empire architecture.

Which roof, the classic shape of the American barn, has two slopes on each side, the lower one steeper?

Gambrel roofs break each side into a shallow upper slope and a steep lower one, which maximises headroom on the upper floor while keeping the whole roof from rising too tall.

Which roof shape stands up to hurricanes better because it has no flat gable ends to catch the wind?

Hip roofs slope down to the walls on every side, so the wind finds no flat gable end to push against; the shape also braces itself, needing less diagonal bracing than a gable roof.

What is a window that stands upright in its own small projection from a sloping roof called?

A dormer takes its name from the French for 'sleeping room', because such windows lit attic bedrooms; a slender one set into a Gothic church spire is called a lucarne.

In US roofing, slope is expressed as inches of rise over what horizontal run?

12 inches is the standard run, matching the tables stamped on a steel framing square, which turn a slope such as 6:12 straight into the lengths and angles to cut.

On Gothic cathedrals, which carved stone figures are really spouts that throw rainwater clear of the walls?

Gargoyles take their name from the Old French for 'throat': rain runs off the roof, through the figure and out of its mouth, sparing the mortar below; a carving with no spout is a grotesque.

The strip of flashing along the downslope face of a chimney is traditionally called what?

An apron is the flashing piece across the chimney's downslope face; step and counter flashing dress the sides, and a back gutter takes the uphill run-off.

According to the Oxford English Dictionary, the word 'eaves' comes from an Old English word meaning what?

Edge is the sense of Old English efes, a singular noun; because it ended in -s, English later took 'eaves' for a plural and coined the new singular 'eave' in the 1500s.

Henry Palmer's 1829 patent gave the world which light, strong roofing, a fixture of Australian farm buildings since the 1840s?

Corrugated iron came from Henry Palmer, engineer to the London Dock Company; the wavy sheets proved light, strong and easy to ship, which suited prefabricated buildings and farms from Argentina to New Zealand.

Overlapping tiles called imbrex and tegula covered the roofs of which ancient civilisations?

Greece and Rome both roofed this way, flat tegulae with half-pipe imbrices capping the joints; in Rome the tiles took over from wooden roofing, and the Greeks even cut some in marble for temples.

In which country is Lerna's 'House of the Tiles', where thousands of Bronze Age terracotta roof tiles were found?

Greece is home to Lerna, where myth set Heracles against the Hydra; its House of the Tiles burned down in about the 22nd century BC, and the ruin with its fallen roof tiles was sealed under a low mound.

The first major sports venue with a retractable roof, a 1961 dome of stainless steel, stood in which US city?

Pittsburgh's Civic Arena was built for the Civic Light Opera, and six of its eight roof sections could fold back in about two and a half minutes; hockey's Penguins later called it home until 2010.

How many tiles cover the shells of the Sydney Opera House?

About 1,056,000 tiles cover the shells; from a distance they look plain white, but glossy tiles are bordered with matte ones, a contrast the architect Jørn Utzon chose so the roof's structure would show.

The Sydney Opera House's roof tiles were made by the firm Höganäs in which country?

Sweden's Höganäs usually made stoneware tiles for paper mills; it spent three years developing the 'Sydney Tile' to get the finish the Danish architect Jørn Utzon wanted.

Almost 2,000 years after it was built, the Pantheon in Rome still holds what record?

Largest unreinforced concrete dome: its builders graded the concrete, with heavy stone low down and light pumice near the top, which helps 43 metres of dome stand with no steel inside.

Who popularised the geodesic dome and patented its design in 1954?

Buckminster Fuller popularised the geodesic dome and patented it in 1954, though Walther Bauersfeld's planetarium dome, 'The Wonder of Jena', had opened in Germany in 1926.

Over decades, a copper roof weathers to which distinctive colour?

Green is the colour of the patina, sometimes called verdigris, that slowly forms on weathered copper, as on the Statue of Liberty; makers now sell pre-patinated sheet so a new roof can match an old one.

The colourful domes that crown St Basil's Cathedral in Moscow are of which type?

Onion domes are a hallmark of Russian churches, yet the historian Wolfgang Born traced the shape to Syria, where mosaics from the Umayyad era already show bulbous domes.

By tradition, the rooster on a church weather vane recalls which apostle?

Peter denied Jesus three times before the cock crowed, and Pope Gregory I called the cockerel the most suitable emblem of Christianity; the oldest surviving rooster vane, in Brescia, dates from 820.

The Tower of the Winds in ancient Athens carried a weather vane in the shape of which sea god?

Triton, a bronze merman, turned on a pivot atop the tower, and the rod in his hand pointed to the carved figure of whichever wind was blowing.

The 'widow's walk', a railed rooftop platform on old coastal houses, is supposedly named after what?

Wives watching for husbands' ships is the romantic story, the watcher left a widow when the sea kept her sailor; the platforms may equally have been built to reach the chimney and fight chimney fires.

Which New England house style has two storeys at the front and one at the back under a long sloping rear roof?

Saltbox houses often got their shape when a lean-to kitchen was built onto the back of a two-storey house; the name comes from the slant-lidded wooden boxes salt was once kept in.

Which architect first designed a V-shaped butterfly roof, for a 1930 holiday house in Chile?

Le Corbusier drew the V-shaped roof for the Maison Errázuriz in 1930; it became a mid-century icon after William Krisel put it on tract houses in Palm Springs from 1957, though Krisel said he was not its originator.

Why were some of the Houston Astrodome's roof panes painted white in 1965?

"Glare stopped players tracking fly balls" through the Lucite skylights, so panes were painted over; the fix killed the natural grass, the Astros played on painted dirt, and in 1966 the dome got the first AstroTurf.

What was the roof turret that let hearth smoke out of a medieval hall called?

A louvre was a lantern-like turret over the roof opening, letting smoke out while keeping rain off; once chimneys arrived, in big houses from the 1100s, a hall no longer needed its height and could be floored over.

A traditional Scandinavian sod roof sits on layers of which material laid over the roof boards?

Birch bark is the real waterproof layer, laid in several sheets over the roof boards; the turf on top is mainly there to hold the bark in place, so it could as fairly be called a bark roof.

Which US city hall's green roof, planted as a microclimate experiment, is among the best known in America?

Chicago City Hall's roof garden, finished in 2001, was a pilot to see how planting cools a city roof and soaks up rain; on a hot afternoon it stays far cooler than the dark conventional roof next door.

An ice dam forms where on a heated building's sloped roof?

At the eaves the roof overhangs unheated space, so meltwater running off the warm attic refreezes there, backing water up under the shingles.

Besides beams cut and fixed on site, modern timber roofs are mostly framed with which prefabricated components?

Wooden trusses arrive ready-made, their joints pressed together with toothed metal plates, which John Calvin Jureit devised in the 1950s to hold by their own teeth alone.

Which hazard is the leading cause of death in roofing, one of America's most dangerous building trades?

Falls killed US roofers at about ten times the rate for construction as a whole in 2017, which is why federal rules demand fall protection for work six feet or more above the level below.

In Australia, what is the tradesperson who builds a house's timber roofing frame called?

A roof carpenter builds the timber frame in Australian usage, while "roofer" there means the trade that fits the cladding of tiles or metal sheeting.

Which Grand Slam's main court got a retractable roof in 2009?

Wimbledon's Centre Court first closed its roof on 29 June 2009, mid-match between Amélie Mauresmo and Dinara Safina; Andy Murray then beat Stan Wawrinka under it, finishing at a then-record 10:38 pm.

What are wooden roofing pieces called when they are split from a log rather than sawn?

Shakes are split from a log along the grain, giving a rough, thick face, whereas shingles are sawn smooth on both sides and laid thinner.

Whose paintings suggested Fiddler on the Roof's title and inspired its original set design?

Marc Chagall's paintings of fiddlers floating over village roofs gave the musical its title, and Boris Aronson's original sets echoed his style; the writers had considered simply calling it Tevye.

The word 'roof' comes from Old English hrof, which also figuratively meant what?

Heaven or sky was the figurative sense of hrof, alongside "top, summit"; English alone kept the word, while other Germanic languages use forms related to thatch, such as German Dach.

In the UK, what is the condition called when a slate roof's corroded fixing nails let slates slip?

Nail sickness sets in when the fixing nails corrode and let sound slates slip, often the first thing to fail on a slate roof; copper or stainless-steel nails are recommended to avoid it.

Which 1851 iron-and-glass building had a roof its designer, a gardener, based on his own greenhouses?

Paxton's Crystal Palace used the ridge-and-furrow glass roof he had devised for the Duke of Devonshire's hothouses at Chatsworth, and a house he built there for a giant Amazon water lily led directly to its design.

Which French cathedral got its vast copper roof after an 1836 fire destroyed the timber one?

Chartres lost its old timber roof in 1836 when workmen's carelessness started a fire; the copper replacement sits on an iron frame, and the medieval stained glass came through untouched.

Galvanised steel roofing sheets are protected from rust by a coating of which metal?

Zinc keeps working even where the coating is scratched, because it corrodes in place of the steel beside the gap; the sheets are usually coated by dipping them in a bath of molten zinc.

Which band gave its final public performance on the rooftop of its London headquarters in January 1969?

The Beatles played a 42-minute set atop Apple Corps at 3 Savile Row before police arrived and told them to turn the volume down.

Which US president had solar water-heating panels installed on the White House roof in 1979?

Jimmy Carter dedicated the 32 panels on the West Wing in 1979; they were taken down in 1986, during roof resurfacing under Ronald Reagan.

Homes on which Atlantic island group have white stepped limestone roofs built to catch every drop of rain?

Bermuda has no rivers or freshwater lakes, so the law requires every household to collect the rain that runs off its roof into a tank.

Neolithic Çatalhöyük in Turkey had no streets between its packed houses, so how were most homes entered?

Holes in the ceiling, reached by ladders, were the usual way in: the flat rooftops were effectively the town's streets.

In Beijing's Forbidden City, almost every roof is tiled in which colour, once reserved for the emperor?

Yellow was the emperor's colour, so nearly every roof wears it; the imperial library got black tiles instead, because black stood for water and so for protection from fire.

In the builders' ceremony of 'topping out', what is traditionally fixed to a new building's highest beam?

A tree or leafy branch goes up with the last beam, a custom traced to an old Scandinavian rite meant to appease the spirits a new building displaced.

Which company unveiled the 'Solar Roof', a home roofing product that generates electricity, in 2016?

Tesla had Elon Musk present the Solar Roof in 2016, but the company only began making it in volume in March 2020.

Scrap-metal thieves in Britain have repeatedly stripped which heavy metal from the roofs of old churches?

Lead was among the first metals ever smelted, and its low melting point made it easy to form into watertight sheets, which is why so many old churches still wear it.

Which 2005 hurricane peeled away part of the Louisiana Superdome's roof while thousands sheltered inside?

Katrina's high winds tore off a large section of the outer covering, and the stadium stayed closed until the Saints' home opener in September 2006.

Which tiered tower, common across East Asia, has a separate projecting roof on each of its storeys?

A pagoda almost always has an odd number of tiers, usually between three and thirteen, and traces its origins to the Indian stupa.

Which playwright won the 1955 Pulitzer Prize for Drama with Cat on a Hot Tin Roof?

Tennessee Williams counted the play as his personal favourite, and the 1958 film version starred Elizabeth Taylor as Maggie.

Whose copper company sheathed the leaking dome of the Massachusetts State House in 1802?

Paul Revere's Revere Copper Company covered the leaky original, and the dome was only gilded with gold leaf in 1874.

Frank Gehry clad the curving Guggenheim Museum Bilbao in some 33,000 thin plates of which metal?

Titanium won out after Gehry watched a sample pinned up outside his office change with the weather and light; the museum's roughly 33,000 sheets are extremely thin.

Which Renaissance architect engineered the vast brick dome of Florence Cathedral, completed by 1436?

Filippo Brunelleschi built it without the usual supporting framework, because Tuscany did not have enough timber to scaffold a dome that size.

Visitors climb spiral ramps inside the glass dome of the Reichstag, the parliament building of which city?

Berlin's dome, designed by Norman Foster, lets the public walk above the debating chamber to symbolise that the people stand above the government.

The white fabric roof of which US city's international airport was designed to resemble snow-capped mountains?

Denver's Jeppesen Terminal also evokes the teepees that once stood across the Great Plains, and a 2003 blizzard dumped enough snow to rip the fabric open.

Fibre-cement roofing sheets, nicknamed 'fibro', were originally reinforced with fibres of which mineral?

Asbestos made the sheets cheap and fireproof, but weathered roofs shed toxic fibres, so it was phased out and cellulose now does the reinforcing.

Which American invented the lightning rod, a pointed rooftop conductor first fitted to buildings in Philadelphia?

Benjamin Franklin tested rods on his own house before they went up in 1752 on the Pennsylvania State House, where independence was later declared.

Which city's SkyDome opened in 1989 with a fully retractable motorised roof?

Toronto's stadium, now Rogers Centre, had to shut that roof mid-game in 2001 when a swarm of thousands of aphids descended on the field.

Which housing term meant an attached building with a sloping roof or awning in 16th-century English?

Penthouse comes from Old French 'apentis', an attached building; its spelling was reshaped by 'pente', slope, and luxury rooftop flats only arrived in the 1920s.

EPDM, a membrane widely used to waterproof flat roofs and line garden ponds, is a synthetic form of what?

Rubber in this form shrugs off hot and cold water alike, and it does not pollute the rain running off it, which suits anyone collecting rainwater.

The gold-plated roof of the Dome of the Rock, regilded in the 1990s, shines over which city?

Jerusalem's shrine was regilded after King Hussein of Jordan sold one of his London houses in 1993 to pay for 80 kilograms of gold.

Which city's St Stephen's Cathedral has a roof of glazed tiles that form a double-headed eagle?

Vienna's cathedral roof is 111 metres long, and its eagle mosaic was the symbol of the Habsburg empire once ruled from the city.

The twelve 100-metre support towers of London's Millennium Dome, now The O2, each stand for what?

A month of the year is one reading and an hour on the clock face the other, both saluting the part played by Greenwich Mean Time.

Which US city long required a rooftop water tower on every building taller than six storeys?

New York has had the rule since at least the 19th century, and the tanks have long been built by family firms in business since then.

Which US president, an early champion of tin roofing, fitted a tin roof to his own Virginia mansion?

Thomas Jefferson put the roof on Monticello at a time when tin was far more common in Canada than in the United States.

Which Manhattan skyscraper is crowned with a sunburst of ribbed stainless steel called Nirosta?

The Chrysler Building's curved crown meant every sheet had to be measured on site and cut in workshops set up on the 67th and 75th floors.

Norman Foster's firm roofed the Great Court of which London institution with 1,656 pairs of unique glass panes?

The British Museum's court was opened by Queen Elizabeth II in 2000, and its rippling roof means no two panes are the same shape.

Which Canadian city's Olympic Stadium was designed with a retractable roof that took until 1987 to complete?

Montreal's Kevlar roof arrived a decade late, kept ripping and was opened and closed only 88 times before a fixed roof replaced it.

Roofers in North America measure a roof and price the job by which unit of area?

A square is 100 square feet, a unit used in the United States and Canada, so a 2,000-square-foot roof takes 20 of them before waste is counted.

Which medieval London landmark has a vast oak hammerbeam roof commissioned for King Richard II in 1393?

Westminster Hall's roof, one of the largest clear-span medieval roofs in Europe, used timber hauled from royal forests by teams of horses.

Which vocal group first recorded 'Up on the Roof', the 1962 hit written by Gerry Goffin and Carole King?

The Drifters' recording later ranked 114th on Rolling Stone's list of the 500 greatest songs; Goffin took the rooftop setting from West Side Story.

A snowstorm in December 2010 collapsed the air-supported fabric roof of the Metrodome in which city?

Minneapolis saw snow and storms damage that roof five times, deflating it on four occasions, and fans used revolving doors so the air pressure holding it up could not escape.

The trulli of Alberobello, dry-stone huts with conical roofs, are a World Heritage site in which country?

Italy's trulli, a tradition of Apulia, use no mortar; one popular theory says that let owners pull them down quickly when the tax inspectors came round.

Japan's steep-roofed gassho-zukuri farmhouses, preserved at Shirakawa, are named for their likeness to what?

Hands in prayer is the image behind the name, and the villages of Shirakawa and Gokayama that keep the style are a UNESCO World Heritage Site.

The golden shachi on the roof of Japan's Nagoya Castle have the body of a carp and the head of which animal?

Tiger-headed shachi were believed to control the rain, so builders set them on rooftops as a talisman against fire.

Which mythical bird, cast in bronze, perches on the roof of Kyoto's Golden Pavilion, Kinkaku-ji?

A phoenix tops a pavilion that had to rise again itself: a novice monk burned the original down in 1950, and the present one dates from 1955.

The Golden Roof, 2,657 gilded copper tiles made for Emperor Maximilian I, shines in which Austrian city?

Innsbruck's landmark was finished in 1500 to mark the emperor's wedding to Bianca Maria Sforza.

Frei Otto's sweeping tent roof of cables and acrylic glass covers the Olympic stadium in which city?

Munich's roof was sparked by a newspaper article: an employee of the architects read about Otto's tent at the 1967 World Fair and proposed one for the stadium.

Roof-window maker Velux, founded in 1941 by Villum Kann Rasmussen, comes from which Nordic country?

Denmark's Velux takes its name from 'VE' for ventilation and 'lux', the Latin for light.

The Hospices de Beaune, a hospital roofed in patterned glazed tiles, is a landmark of which French wine region?

Burgundy made such roofs its trademark, and others survive in Dijon, though the Hospices tiles seen today are replicas laid between 1902 and 1907.

Which Central Asian country's flag shows a tunduk, the crown ring at the top of a yurt's roof?

Kyrgyzstan's flag sets the ring inside a sun on a red field, drawn the way it looks from inside the tent, gazing up.

The upswept roof peaks of a Minangkabau rumah gadang in Sumatra are said to represent the horns of which animal?

A buffalo fight is at the heart of the legend from which the Minangkabau people are thought to take their name.

At which Irish passage tomb does the winter solstice sunrise shine through a 'roofbox' above the entrance?

Newgrange lets the dawn light run down its passage and flood the inner chamber, and it is one of the few passage graves with such an opening.

Which architect gave the 1962 TWA Flight Center at JFK Airport its soaring, wing-like shell roof?

Eero Saarinen's roof recalled the 'gull wing' of the Chevrolet Impala, made by General Motors, whose Technical Center he had also designed.

The inflated roof cushions of the Eden Project's biomes in Cornwall are made from which plastic film?

ETFE film is sealed in layers and inflated into pillows; punctures are simply patched with tape, and most dirt washes off in the rain.

Which term do scientists use for the solar reflectance that a white-painted 'cool roof' is designed to raise?

Albedo slips as a surface gets dirty, so a cool roof has to be kept clean if it is to go on saving energy.

Which genus of hardy succulents can carpet a planted roof on nothing more than a thin layer of rockwool?

Sedum needs so little soil that Ford planted the vast assembly-plant roofs of its River Rouge works in Michigan with it.

Which S-shaped clay roof tile, first imported to Britain from the Netherlands, is common in eastern England?

A pantile laps only the course below, so a roof of them is considerably lighter than one of flat tiles and can be laid to a lower pitch.

In the Gospel story of a paralysed man lowered through a roof to reach Jesus, in which town does it happen?

Capernaum's crowd left no room even outside the door, so the man's friends dug an opening through the roof and lowered him on his mat.